Fastener applying tool

ABSTRACT

A tool for applying resilient C-type clips to the edges of perforated panels for the reception of screw-type fasteners includes a pair of locating fingers adapted to overlie the surface of the panel, to locate the tool against vertical displacement, a hook-type locator engageable in the fastenerreceiving aperture in the panel for horizontal and radial alignment, and a pusher adapted to hold a clip prior to installation and to force the clip into overengaged relation with the panel in registry with the fastener aperture. The stroke of the pusher is so related to the position of the hook-type locator and to the proportions of the clip that actuation of the pusher through a full stroke moves the clip into registry with the aperture in the panel regardless of the distance between such aperture and the edge of the panel.

United States Patent Munse 1 Nov. 14, 1972 [54] FASTENER APPLYING TOOL [72] Inventor: Robert A. Munse, Troy, Mich.

[73] Assignee: Microdt, Inc., Greenwich, Conn.

22 Filed: May 6, 1971 21 Appl. NO.Z 140,658

52 us. c1. .29/225 51 im. c1. ..B23p 19/04 [58] Field of Search ..29/225, 229, 249, 211 M 56 References Cited UNITED STATES PATENTS 3,501,827 3/1970 Munse ..29/225 3,040,419 6/1962 Erdmann ..29/229 x 2,895,214 7/1959 Erdmann ..29/229 1,633,110 6/1927 Koons ..29/249 Primary Examiner0thell M. Simpson Attorney-Harness, Dickey & Pierce ABSTRACT A tool for applying resilient C-type clips to the edges of perforated panels for the reception of screw-type fasteners includes a pair of locating fingers adapted to overlie the surface of the panel, to locate the tool against vertical displacement, a hook-type locator engageable in the fastener-receiving aperture in the panel for horizontal and radial alignment, and a pusher adapted to hold a clip prior to installation and to force the clip into overengaged relation with the panel in registry with the fastener aperture. The stroke of the pusher is so related to the position of the hooktype locator and to the proportions of the clip that actuation of the pusher through a full Stroke moves the clip into registry with the aperture in the panel regardless of the distance between such aperture and the edge of the panel.

14 ll Drawing i igures PATENTED nuv 14 1912 sum 2 or '5 j; w E

/%A ri /7 $25253.

FASTENER APPLYING TOOL BACKGROUND OF THE INVENTION In the high production assembly of sheet-like materials it is common practice to employ nut fasteners in the form of C-clips, through which screws may be passed to secure the parts together. Various types of special tools have been designed to install C-clips upon panel surfaces in registry with preformed screw apertures. The overall objective of the present invention is to provide an improved tool for the indicated purpose which is effective to install such C-clips quickly and reliably, and in accurately registered relation to panel apertures, even through the distances between the apertures and the edge over which the clip is fitted vary widely, and wherein no special adjustment of the tool'is necessary to install clips over such variantly spaced apertures. A further object is to provide such a tool which is light in weight yet simple and rugged and which in operation is easy and natural for the workman to place and hold in the proper position for clip installation, and the angular positioning of which for such purpose is not critical.

Still another object is to provide improved means for feeding the clips to holding means on the ram of the tool.

Other objects and advantages will become apparent upon consideration of the present disclosure in its entirety.

BRIEF DESCRIPTION OF THE FIGURES OF DRAWING FIG. 1 is aside elevational view of a power-operated tool constructed in accordance with the present invention;

FIG. 2 is a side elevational view on a larger scale showing operating and locating head portions of the tool, with the ram retracted and a clip in place on the tool ready for installation;

FIG. 3 is a view similar to FIG. 2 showing the ram fully projected and a clip installed on the panel;

FIG. 4 is an end elevation viewed as from the right of FIG. 2;

FIG. 5 is a bottom plan view of the portion shown in FIG. 2 corresponding to a section on the line V-V of FIG. 2 looking in the direction of the arrows, the clip nut and feeding means being omitted;

FIG. 6 is a sectional view of mechanism for inserting clips into and propelling them through the clip feed hose;

FIG. 7 is a sectional elevational view of a modified tool designed for manual operation;

FIG. 8 is a view similar to FIG. 7 of another form of manual tool, partly broken away;

FIG. 9 is a cross section taken substantially on the line IX-IX of FIG. 8 and looking in the direction of the arrows;

FIG. 10 is a perspective view of a clip nut of a type adapted to be installed by my improved tool; and

FIG. 1 l is a schematic diagram.

DETAILED DESCRIPTION OF PREFERRED FORMS OF THE INVENTION The power-operated tool shown in FIGS. 1-6 constitutes an improvement upon the invention disclosed in US. Pat. No. 3,50l,827 granted to me under date of Mar. 25, 1970. The tool is of a size and weight to be operated with one hand, being provided with a pistollike body including a hand grip portion 10 and a barrel portion 22. The trigger 12 operates an air valve 14 which is opened, when the trigger is pressed, to admit air under pressure to the rear end of cylinder 20 carried on top of the barrel. The air is supplied through a hose l5 and when the trigger valve is opened, enters the cylinder 20 through a connecting elbow 25 which conveys the air to the rear of the cylinder. Elbow 25 and a forward bracket 24 cooperate to support the cylinder, which is of a conventional spring-retumed type. Its piston 26 has a hexagonal rod 28 extending forwardly from the cylinder through a conforming hexagonal opening 30 in the front cylinder head 32.

The cylinder head 32 is secured to the end of the cylinder by a nut 33 and has an extension bracket portion 34 of rectangular section which supports a pair of rigidly attached laterally spaced forwardly extending locating arms 35, 36. The arms 35, 36 are adapted to overlie the panel near the edge, when the tool is in use (as shown in FIG. 2) and when rested thereupon support the weight of the tool, maintaining it against vertical displacement during operation.

A rarn assembly generally designated 40 attached to the end of piston rod 28 is slidably mounted between arms 35, 36. The ram assembly is rigidly but adjustably connected to the forward end of the piston rod 28 by means of an elongated coupling nut 42 which at one end is threadably overfitted upon the conformably threaded forward extremity 43 of the piston rod while the other end of the nut is tightly securable to the ram .by the screw 44. The axial length of the nut 42 maintains a clearance between the abutting ends of the piston rod extremity 43 and screw 44, so that when the screw 44 is loosened, the nut may be turned to change the longitudinal positioning of the ram with respect to the piston, whereafter tightening the screw 44 maintains such adjustment.

Also rigidly supported by the bracket portion 34 is a locating hook comprising a stern portion 46 which extends forwardly parallel to the cylinder axis and the locating arms 35, 36 midway between the latter and in vertical alignment with the cylinder axis. At a position beyond the outer ends of the arms 35, 36 stem 46 carries an integral downwardly extending rigid terminal hook portion 48 having a rearwardly facing vertical abutment surface 50 and which extends downwardly below the bottoms of the locating arms 35, 36 far enough to project into the aperture 52 in the panel 53 to which the clip is to be applied. In FIG. 2 a C-clip 55 is also illustrated in position on the tool, ready for installation on the panel. The stroke of the piston and ram are so proportioned to the position of the abutment surface 50 and the location of the coaxial nut portion 56 and clearance opening 57 of the clip that when the hook 48 is in the aperture 52 and the tool is pulled back against the near side of the aperture, a full stroke of the ram terminates, at the forward position, with such nut portion and clearance opening in registry with the panel aperture 52. Thus regardless of any differences in the spacing between the edge of the panel and the aperture 52, the clip stops with all openings in proper registry, even though the clip, in order to reach such properly registered position, does not move all the way onto the panel, in those cases where the aperture is closer to the edge of the panel than the distance between the bight of the C-clip and the common axis of the nut and clearance openings in the clip. Such a registered and properly applied clip which, by reason of this operation nevertheless projects from the edge of the panel, is shown in FIG. 3.

The ram assembly 40 comprises a body portion 41 having a downwardly opening longitudinal channel 45 in which are rigidly secured a pusher block 58 and magnet 60. The horizontal bottom holding surface portions 61 of the magnet are coplanar with the bottom surface portions of the forward portion of the pusher block, and these bottom surface portions are at an elevation higher than the bottom surface 62 of the ram body 41. The bottom surface 62 of the ram body is in turn slightly higher than the common plane defined by the flat bottom surfaces 63 of locating arms 35, 36. In the area to the rear of the bottom surface portions 61 of the magnet and pusher block, the pusher block extends downwardly to a level below the locating arms, a vertical clip-pushing shoulder 59 being thereby defined. The channel 45 in the ram body is slightly deeper than the magnet and the forward portion of the pusher block, and the width of channel 45 slightly exceeds the width of the C-clips for which the tool is designed. Thus when a clip is on the bottom retaining surface 61 of the magnet in its proper centered position as shown in FIG. 2 the sides of the clip are slightly overhung by the channel-defining sides of the ram body and the shoulder 59 is directly behind the clip, which is thereby effectively guided during projecting movement of the ram. The magnet and pusher block are also provided with a longitudinal slot 65 providing clearance for the stem 46.

The bottoms of the locating arms 35, 36 are at the lowest elevation, and thus the magnet and other parts of the ram do not rub on the panel during application of the clip. The hook portion 48 of the horizontal locator is relatively narrow, and the clips are provided with a clearance slot 64 in the upper surface extending from the free edge of the upper arm to the clearance opening 57, to permit the bifurcated upper surface of the clip to pass on either side of the terminal hook 48 and into the registered position during application.

The barrel 22 has an air discharge orifice contained in a drilled breather screw 68. In the trigger-released position the valve 14 connects the cylinder to the breather opening, which controls the rate of retraction of the ram, while at the same time closing off the air supply to the cylinder; such connections being reversed by valve 14 when the trigger is depressed.

The means for feeding clips to the ready position shown in FIG. 2 includes a flexible tube 67 through which the clips are fed with their free arms projecting forwardly. The discharge end of tube 67 is secured to the cylinder head 32 by a bracket portion 37 which is integral with the cylinder head and terminates beneath and close to the retracted position of the magnet. The tube approaches such terminal position at an acute angle to the plane of ram movement and the upper portion of the tube is open near the end, as indicated at 66, to permit clips to rise into contact with and be held by the bottom surface of the magnet. The end of the tube 67 is blocked by a wall 69 which forms part of an angle bracket having a bottom flange 70 which is secured to the supporting bracket portion 37. Flange acts as a clamp to secure the tube to the bracket portion 37 The flange 70 also has an upturned bead 71 at its rear end extending into a slot (undesignated) in the bottom of the rectangular tube 67 to lock the tube in place.

Clips are projected through the tube at relatively high speed by airpressure and arrested in their forward movement by the wall 69 to permit them to be attracted upwardly by and come to rest against the bottom of the magnet.

A flexible air hose 73 connected to elbow 25 by a fitting 72 is pressurized whenever air is supplied to the rear end of cylinder 20. Line 73 is connected to suitable actuating means for clip feed apparatus which delivers clips to and through the hose 67. Such feed mechanisms are known, and form no part of my present invention. In the arrangement shown, air pressure in line 73 actuates, by means of a servomotor cylinder 84, a switch 85 which closes momentarily, but only during the pressurized outstrokeof the servomotor piston, to energize and actuate solenoid valves 86, 87. Valve 86 then delivers air for abrief interval from a suitable but unshown source to servomotor cylinder 74 which thereby moves a gate 75, slidable in a clip feeder body 77 located at the entrance end of the tube 67 and controlling the admission of clips to the tube, causing such gate to move first to the left, to the position shown in broken lines, and then back to its right hand (full line) position, as viewed in FIG. 6. The gate thereby acts in a well-known fashion to convey a single clip from a feed track 83 to the tube 67 each time the trigger is pressed. The clip-holding orifice 78 extends entirely through the gate, and air passes therethrough into the tube 67 to propel the clip through the tube. Propelling air under pressure is introduced through a fitting 80 and an air opening 82 in the feeder body 77, in alignment with the tube 67 I The solenoid valve87, which is opened at the same time as valve 86, is held open for a predetermined interval by suitable timing mechanism, shown as a dashpot 88, which maintains valve 87 open long enough to deliver chasing air to fitting 80 via hose 81 for the required interval to propel the clip entirely through the hose 67. The clip and air are delivered to tube 67 via a continuation passage 79 in the body.

The time required for the clip to traverse the feed hole 67 is more than suflicient for the head 40 to retract to the loading position. If desired the trigger-actuated valve 14 may be arranged to deliver an air pulse of limited duration to the cylinder 20 and to tube 73, so that prompt return of the head 40 will occur even if the operator should hold thetrigger down. I

The clips may be fed to the track 83 in properly oriented position by known types of hopper means (not shown) forming no part of the present invention, and are maintained in such orientation during delivery to the ram assembly by the confining effect of the conforming cross sectional configuration of the track, feeder passages, tube and other transport g pa ts.

It will be appreciated that references in the specification and claims to the relative positioning of the work panel 53, and the other disclosed components, and which references are predicated upon the supposition that parts are in a horizontal or other specified position, are merely for convenience of description, and that the work panel and the tool components might be differently oriented, although their relative positionings with respect to one another would remain similar.

In the modified construction shown in FIG. 7 the ram assembly 40A is actuatable by energy stored in a spring during actuation of the trigger, no external source of power being required. Many parts of this embodiment correspond to parts of the first embodiment and will not require redescription. Like reference characters are used, distinguished by the addition of the letter 6 A!!- The ram body 40A is rigidly attached to a stem 100 slidable axially in a cylinder 11A from which the stem projects through the front-end cap-32A. The rear end of the stem has an enlarged head 102 slidable in a chamber 104 in the cylinder. A helical compression spring 105 trapped on the rod between the head 102 and cap 32A biases body 40A to the retracted position.

Axially slidable in the cylinder rearwardly of stem 100 is a cylindrical hammer rod 106 actuatable by an impact spring 108. The rear end of the hammer rod is attached to a cylindrical spring abutment 110 slidable in a chamber 111 so that the hammer is urged forwardly by the spring 108.

The front bracket 37A fixedly carries locating fingers 35A, 36A and locating stern 46A, corresponding to the analogously designated parts of the first-embodiment, and bracket 37A also serves as an attachment member for the feed hose 67A in similar fashion. The stroke of the ram head is so related to the position of the forwardly directed abutment face 50A of the locating stem 46A that when face 50A is held against the farther wall of the hole 52A in the work, the forward limit of ram movement is at a position to properly align the nut opening in the clip with the work hole.

The spring 105 is relatively weak and serves only to return the ram assembly when the hammer is withdrawn against the force of the heavier spring 108.

Means are provided to draw back the hammer and compress the spring 108 between slidable abutment 110 and rear end cap 112, such means comprising a trigger 12A supported for rectilinear sliding movement in handgrip 10A by stems 114 and carrying a dog 115 pivoted to its upper end on a transverse axis and yieldably biased upwardly by a torsion spring 116 to project into the path of a lug 118 attached to the abutment 110 and extending downwardly through a slot 120 in the cylinder. A fixed cam 122 projecting downwardly from the bottom of the cylinder 11A is engageable with a lug 124 projecting laterally from the dog 115 to move the dog downwardly and clear of the lug 118 when the hammer has been pulled back to a desired extent, the hammer being thus freed to be projected by the spring 108. The momentum of the hammer assembly drives the head A forwardly with sufficient force to install the clip on the panel in a manner similar to the operation of the first embodiment. The abutment portion 110 of the hammer may be of substantial mass, and since the first portion of the travel of the hammer is not opposed by the spring 105, the energy derived from the inertia imparted to the hammer assembly may be sufficient to overcome the resistance of spring 105 with a lesser force requirement on the part of spring 108 than would otherwise be necessary. The spring 108, being thus lighter than would otherwise be required, the efiort required on the part of the workman is correspondingly reduced.

In operation, the workman places the tool over the top surface of the panel and pushes the abutment face 50A of stem 46A against the farther surface of the hole 52A in the work, and pulls the trigger while holding the tool in this position, the hammer being tripped to drive the head and fastener as the rearward movement of the trigger is completed, in the manner described.

During the rearward movement of the head 40A, and at a position close to the completion of such rearward movement, the feeding means corresponding to the construction illustrated in FIG. 6 and previously described is tripped by a suitable electric switch (not shown) to feed a clip to the holding magnet A, the rate of feed of the clip through the hose being rapid enough and so timed that the clip arrives at the holding portion of the magnet as the latter is withdrawn to the proper position to receive it.

In FIG. 8 another modified manually-operated tool is illustrated, designed to permit the fasteners to be directly pushed onto the work. Parts corresponding to those already described are designated by like reference numerals distinguished by the letter B.

The ram body 4013 is rigidly attached to a handle by a straight forwardly projecting arm 288 in the shape of a downwardly opening channel, in the open front end of which the ram body is fixedly secured by screw means 91, 93. In place of the cylinder head 32 a bracket body 92'is provided, slidably but-non rotatably fitted in the arm 28B and carrying bracket portions 24B, 37B which respectively support in similar fashion the locating components comprising stem 46B and arms 35B, 36B, and the discharge end of the feed tube 67B. The stroke of the ram with relation to the locating stem 46B is fixable by an adjustable abutment 94 to accommodate clips of different lengths. The terminal portion 488 of the stem 468 has an abutment surface 50B facing forwardly away from the ram, rather than back toward it as in thefirst embodiment.

A helical tension spring is connected at one end to a post 97 secured to the top of bracket body 92. Post 97 projects slidably upwardly through a slot 98 in the top of arm 28B, and the spring 95 extends forwardly on top of the arm to connection with screw member 93 which is shaped as a spring post, as shown in FIG. 8. Slot 98 also accommodates the adjustable abutment 94, which is formed as a screw having its head in the channel in the path of the bracket body 92 and its stem extending upwardly through and above the slot to receive a wing nut 96.

In operation the terminal portion 48 of stem 46B is placed in the panel aperture, with arms 35B, 36B, resting on the panel in overlying relation as with the previous embodiments, and the ram is then pushed forward manually by the handle 90 to push a clip onto the panel, while the locating parts are held against forward movement by abutment surface 50B. The stroke is set by means of abutment 94 so that the ram stops in such relation to surface 50B as to properly register the clip with the panel aperture.

It will be seen that after applying the clip the tool may be lifted free of the panel, and that as soon as the terminal hook 48B leaves the aperture the locating parts will be moved forward relatively to the ram by the a feed gate corresponding to gate 75 and cause another clip to be fed to the tool.

Although the abutment hooks 48, 48A and 48B are shown rigidly carried by their respective stem portions 46, 46A, 468, which necessitates use of clips having a bifurcated arm to overlie the panel, it will be understood that such hook portions might be retractable, as disclosed in U.S. Pat. No. 3,501,827, to permit use of clips having merely a clearance opening such as 57 in the overlying arm; need for the slot 64 (FIG. thereby being eliminated.

In the first embodiment the ram head 40 is guided by the hexagonal piston rod and is also guided between the arms 35, 36. In the second embodiment similar guiding is furnished by the hexagonal stem 100 and by the arms; the openings in heads 32, 32A being of conforming cross section in those two embodiments. In the embodiment of FIGS. 8 and 9 the a relative movement between the arm 28B and the assembly which comprises the support collar 92 and the locating and positioning arms 35B, 36B, 46B, is guided by interfitted longitudinal keying and keyway portions 125, 126, the keying portions comprising bars 125 secured to the inner sidewalls of the arm channel 28B, the bars being slidable in the keyway slots 126 in the outer surfaces of arms 35B, 36B.

This Detailed Description of Preferred forms of the invention, and the accompanying drawings, have been furnished in compliance with the statutory requirement to set forth the best mode contemplated by the inventor of carrying out the invention. The prior portions consisting of the Abstract of the Disclosure and the Background of the Invention are furnished without prejudice to comply with administrative requirements of the Patent Ofiice.

What is claimed is:

1. In a tool for installing a nut fastener or like element of predetermined dimensions upon a workpiece having a substantially flat surface and having an opening therein, such element also having an opening therein intended for alignment with the opening in the workpiece, said tool having a combined holder-pusher for such an element, actuating means and guide means for moving the holder-pusher backwardly and forwardly between a retracted position clear of the workpiece and a projected position overlying the workpiece in a path parallel to said surface, a locating arm fixed with relation to said guide means and extending forwardly therefrom substantially parallel to said path and an abutment on said arm secured against unwanted movement in a direction parallel to said path and extending laterally of said path for insertion into the opening in the workpiece, the novelty which comprises means limiting the forward movement of the holderpusher to a projected position so related to the dimensions of said element and to the position of the abutment that when the abutment is in the opening in a workpiece and the holder-pusher reaches the projected position, the opening in an element carried thereby is aligned with the opening in the workpiece, without regard to the distance between the latter opening and the edge or other areas of the workpiece.

2. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which later position the opening in the element extends around the abutment.

3. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, a hand grip portion connected to the guide means for holding the latter and the abutment stationary while the thrust element and holder-pusher move forwardly, the abutment having a restraining surface facing rearwardly toward the handgrip portion.

4. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the'retracted to the projected position in which latter position the opening in the element extends around the abutment, an actuating handgrip portion connected to the thrust element to move the latter and the holder-pusher forwardly by manual effort, the abutment having a restraining surface facing forwardly away from the handgrip portion to restrain forward movement of the guide means during such movement of the holder-pusher.

5. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retractedto the projected position in which latter position the opening in the element extends around the abutment, a hand grip portion connected to the guide means for holding the latter and the abutment stationary while the thrust element and holder-pusher move forwardly, the abutment having a restraining surface facing forwardly toward the handgrip portion.

6. A tool as defined in claim 1 wherein said means for limiting the movement of the holder-pusher comprises means for fixedly securing the holder-pusher in different positions with respect to the actuating means.

7. A tool as defined in claim 1 wherein said means for limiting the movement of the holder-pusher comprises an adjustable stop for arresting at desired positions the forward movement of the holder-pusher relatively to the abutment.

8. In a tool for installing a nut fastener or like element of predetermined dimensions upon a workpiece having a substantially flat surface and having an opening therein, such element also having an opening therein intended for alignment with the opening in the workpiece, said tool having a combined holder-pusher for such an element, actuating means and guide means for moving the holder-pusher backwardly and forwardly between a retracted position clear of the workpiece and a projected position overlying the workpiece in a path parallel to said surface, a locating arm fixed with relation to said guide means and extending forwardly therefrom substantially parallel to said path and an abutment on said arm secured against unwanted movement in a direction parallel to said path and extending laterally of said path for insertion into the opening in the workpiece, the novelty which comprises a pair of locating fingers fixed with relation to said locating arm and spaced laterally from the direction of lateral projection of said abutment and adapted to overlie the workpiece at positions spaced from the opening therein while the abutment is in said opening, to restrain unwanted movement of the tool in a direction parallel to the axis of such opening.

9. A tool as defined in claim 8 wherein said fingers are also spaced from said path in the same direction as said abutment but less than the distance of the maximum lateral extension of said abutment, whereby the holder-pusher is held spaced from the surface of the workpiece during its travel in overlying relation thereto,

10. A tool as defined in claim 9 wherein said fingers include supporting arm portions extending substantially parallel to said locating arm, said locating arm and said arm portions being substantially straight and parallel to said path whereby the bottoms of said arm portions may lie upon the surface of the workpiece in coplanar relationship thereto, the path of the bottom of the holder-pusher and the bottom of the locating arm being spaced above such plane and the abutment extending below such plane.

11. In a tool for installing upon a workpiece a nut fastener or like element formed of magnetic material, including a combined holder-pusher for such an element, supporting guide means for the holder-pusher, actuating means for moving the holder-pusher backwardly and forwardly relatively to said supporting guide means between a retracted reloading position and a projected installing position, magnetic holding means on the holder-pusher for retaining the element during such movement, and means for feeding such elements one at a time to the holder-pusher when the latter is in reloading position comprising a delivery tube having a laterally directed discharge opening adjacent and generally parallel to a magnetic surface of the holding means when the latter is in reloading position, whereby such elements may be attracted by and to such magnetic surface laterally of the tube through said discharge opening, the novelty which comprises a blocking wall extending transversely of the tube across the discharge end of said tube appurtenant to said opening to arrest forward movement of such elements through the tube prior to their movement laterally through said opening.

12. A tool as defined in claim 11 including a handle portion for manually supporting and maneuvering the tool, and means for fixedly positioning the discharge end of the tube with respect to. the supporting guide means.

13. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, and manuall actuatable means for moving the thrust element an the holderpusher forwardly while the guide means is restrained by said abutment.

14. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, and manually actuatable means for moving the thrust element and the holderpusher forwardly while the guide means is restrained by said abutment, said manually actuatable means comprising a trip hammer and a grippable actuator therefor. 

1. In a tool for installing a nut fastener or like element of predetermined dimensions upon a workpiece having a substantially flat surface and having an opening therein, such element also having an opening therein intended for alignment with the opening in the workpiece, said tool having a combined holder-pusher for such an element, actuating means and guIde means for moving the holder-pusher backwardly and forwardly between a retracted position clear of the workpiece and a projected position overlying the workpiece in a path parallel to said surface, a locating arm fixed with relation to said guide means and extending forwardly therefrom substantially parallel to said path and an abutment on said arm secured against unwanted movement in a direction parallel to said path and extending laterally of said path for insertion into the opening in the workpiece, the novelty which comprises means limiting the forward movement of the holder-pusher to a projected position so related to the dimensions of said element and to the position of the abutment that when the abutment is in the opening in a workpiece and the holder-pusher reaches the projected position, the opening in an element carried thereby is aligned with the opening in the workpiece, without regard to the distance between the latter opening and the edge or other areas of the workpiece.
 2. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which later position the opening in the element extends around the abutment.
 3. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, a hand grip portion connected to the guide means for holding the latter and the abutment stationary while the thrust element and holder-pusher move forwardly, the abutment having a restraining surface facing rearwardly toward the handgrip portion.
 4. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, an actuating handgrip portion connected to the thrust element to move the latter and the holder-pusher forwardly by manual effort, the abutment having a restraining surface facing forwardly away from the handgrip portion to restrain forward movement of the guide means during such movement of the holder-pusher.
 5. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, a hand grip portion connected to the guide means for holding the latter and the abutment stationary while the thrust element and holder-pusher move forwardly, the abutment having a restraining surface facing forwardly toward the handgrip portion.
 6. A tool as defined in claim 1 wherein said means for limiting the movement of the holder-pusher comprises means for fixedly securing the holder-pusher in different positions with respect to the actuating means.
 7. A tool as defined in claim 1 wherein said means for limiting the movement of the holder-pusher comprises an adjustable stop for arresting at desired positions the forward movement of the holder-pusher relatively to the abutment.
 8. In a tool for installing a nut fastener or like element of predetermined dimensions upon a workpiece having a substantially flat surface and having an opening therein, such element also having an opening therein intended for alignment with the opening in the workpiece, said tool having a combined holder-pusher for such an element, actuating means and guide means for moving the holder-pusher backwardly and forwardly between a retracted position clear of the workpiece and a projected position overlying the workpiece in a path parallel to said surface, a locating arm fixed with relation to said guide means and extending forwarDly therefrom substantially parallel to said path and an abutment on said arm secured against unwanted movement in a direction parallel to said path and extending laterally of said path for insertion into the opening in the workpiece, the novelty which comprises a pair of locating fingers fixed with relation to said locating arm and spaced laterally from the direction of lateral projection of said abutment and adapted to overlie the workpiece at positions spaced from the opening therein while the abutment is in said opening, to restrain unwanted movement of the tool in a direction parallel to the axis of such opening.
 9. A tool as defined in claim 8 wherein said fingers are also spaced from said path in the same direction as said abutment but less than the distance of the maximum lateral extension of said abutment, whereby the holder-pusher is held spaced from the surface of the workpiece during its travel in overlying relation thereto.
 10. A tool as defined in claim 9 wherein said fingers include supporting arm portions extending substantially parallel to said locating arm, said locating arm and said arm portions being substantially straight and parallel to said path whereby the bottoms of said arm portions may lie upon the surface of the workpiece in coplanar relationship thereto, the path of the bottom of the holder-pusher and the bottom of the locating arm being spaced above such plane and the abutment extending below such plane.
 11. In a tool for installing upon a workpiece a nut fastener or like element formed of magnetic material, including a combined holder-pusher for such an element, supporting guide means for the holder-pusher, actuating means for moving the holder-pusher backwardly and forwardly relatively to said supporting guide means between a retracted reloading position and a projected installing position, magnetic holding means on the holder-pusher for retaining the element during such movement, and means for feeding such elements one at a time to the holder-pusher when the latter is in reloading position comprising a delivery tube having a laterally directed discharge opening adjacent and generally parallel to a magnetic surface of the holding means when the latter is in reloading position, whereby such elements may be attracted by and to such magnetic surface laterally of the tube through said discharge opening, the novelty which comprises a blocking wall extending transversely of the tube across the discharge end of said tube appurtenant to said opening to arrest forward movement of such elements through the tube prior to their movement laterally through said opening.
 12. A tool as defined in claim 11 including a handle portion for manually supporting and maneuvering the tool, and means for fixedly positioning the discharge end of the tube with respect to the supporting guide means.
 13. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, and manually actuatable means for moving the thrust element and the holder-pusher forwardly while the guide means is restrained by said abutment.
 14. A tool as defined in claim 1 wherein the actuating means includes a thrust element connected to the holder-pusher to move an element held thereby forwardly from the retracted to the projected position in which latter position the opening in the element extends around the abutment, and manually actuatable means for moving the thrust element and the holder-pusher forwardly while the guide means is restrained by said abutment, said manually actuatable means comprising a trip hammer and a grippable actuator therefor. 